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A study of high alpha dynamics and flow visualization for a 2.5-percent model of the F-18 HARV undergoing wing rockFree-to-roll experiments and flow visualization studies have been conducted for a 2.5-percent model of the F-18 undergoing unsteady wing rock oscillations. Data have been acquired in the form of roll angle time histories as well as video recordings and 35 mm photography of the forebody and leading edge extension vortices. The time histories were differentiated to produce angular velocity and angular acceleration. From this the roll moment as a function of time and/or roll angle could be estimated. A thorough analysis of the data has revealed a genuine wing-rock phenomenon. Off-surface flow visualization was used to identiify the forebody and LEX vortex core positions and their interaction in both static and dynamic configurations. A direct correlation between the dynamic data and visualized vortex activity during the wing-rock motion has been made.
Document ID
19910069152
Document Type
Conference Paper
Authors
Quast, Thomas (Notre Dame Univ. IN, United States)
Nelson, Robert C. (Notre Dame, University IN, United States)
Fisher, David F. (NASA Flight Research Center Edwards, CA, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1991
Subject Category
AERODYNAMICS
Report/Patent Number
AIAA PAPER 91-3267
Funding Number(s)
CONTRACT_GRANT: NCA2-513
Distribution Limits
Public
Copyright
Other